Applying laser scanning technology to studying alluvial flume-bed topography in laboratory conditions

The aim of the research was to compare alluvial bed topography description in laboratory conditions using the “traditional”, currently applicable method with an original approach, based on LiDAR technology. LiDAR application in local scours shape investigation in based on the grounds of introducing the autonomic measuring module, which, placed above the bed on dedicated controllable arrangement of guideways, describes the landform as a cloud of coordinates. The result of the performed experiment was obtainment of point clouds (x, y, z), reflecting the bed shape before and after local scour formation during twenty measurement series with varying hydraulic conditions. Objects of the study were basic geometry properties of the scour hole and its volume. The measurement with laser scanner technology application allowed for obtaining much more accurate results in shorter time, comparison to disc probe survey, and also relatively fast conversion of numerical data into figures. The device equipped with portable computer, precise stepper motors and dedicated software permitted the introduction of automation into laboratory work. The effect is not only measurements accuracy, but also significant acceleration of data gathering. The adopted grid is characterized by significant density, which – in connection with meaningfully high accuracy – allows very precise surface description. Bed shape can be presented in numerical or graphical form. It must be pointed out that disc probe method application would never give such accuracy as in the case of introducing laser scanning technology in similar studies

The place of MR urography in the diagnosis of urinary tract pathology in pediatric patients. Case report

Wstęp. Urografia rezonansu magnetycznego (uro-MR) jest nowoczesną metodą umożliwiającą nieinwazyjne badanie układu moczowego. Materiał i metody. Przedstawiono przykład wykorzystania obrazowania techniką uro-MR w ustaleniu prawidłowego rozpoznania u dziecka z pa­tologią układu moczowego. Wyniki. U 12-letniej dziewczynki leczonej z powodu obustronnych podwójnych układów kielichowo-miedniczkowych ze zdwojeniem moczowo­dów oraz obustronnych odpływów pęcherzowo-moczowodowych obserwowano nawracające infekcje układu moczowego i zastój moczu. Wyniki badań obrazowych (urografia, cystografia, uro-TK) nie pozwoliły na wyciągnięcie jednoznacznych wniosków . Ostateczne rozpoznanie ustalono na podstawie badania uro-MR. Wnioski. Urografia MR jest skuteczną, niejonową metodą obrazowania układu moczowego u dzieci. W przyszłości należy spodziewać się wzrostu znaczenia uro-MR w diagnostyce patologii układu moczowego w grupie pacjentów pediatrycznych.Introduction. Magnetic resonance urography (uro-MR) is new noninvasive method for evaluation of the urinary tract. Material and methods. We described the examples of application of uro-MR to obtain correct diagnosis in child urinary tract abnormalities. Results. In a 12-year-old girl treated with bilateral duplicated pyelocalyceal system, ureters duplex and bilateral vesicoureteral reflux, recur rent urinary tract infections and urinary tract obstruction were observed. The results of imaging studies (urography, cystography, uro-CT) did not allow us to draw firm conclusions about diagnosis. The final diagnosis was based on uro-MR result. Conclusions. MR urography is useful, nonionizing method for evaluation of the urinary tract. In future, increasing importance of uro-MR in the diagnosis of urinary tract pathology in pediatric patients, may be expected

Over 200,000 kilometers of free-flowing river habitat in Europe is altered due to impoundments

European rivers are disconnected by more than one million man-made barriers that physically limit aquatic species migration and contribute to modification of freshwater habitats. Here, a Conceptual Habitat Alteration Model for Ponding is developed to aid in evaluating the effects of impoundments on fish habitats. Fish communities present in rivers with low human impact and their broad environmental settings enable classification of European rivers into 15 macrohabitat types. These classifications, together with the estimated fish sensitivity to alteration of their habitat are used for assessing the impacts of six main barrier types (dams, weirs, sluices, culverts, fords, and ramps). Our results indicate that over 200,000 km or 10% of previously free-flowing river habitat has been altered due to impoundments. Although they appear less frequently, dams, weirs and sluices cause much more habitat alteration than the other types. Their impact is regionally diverse, which is a function of barrier height, type and density, as well as biogeographical location. This work allows us to foresee what potential environmental gain or loss can be expected with planned barrier management actions in rivers, and to prioritize management actions

Using a Modified Lane’s Relation in Local Bed Scouring Studies in the Laboratory Channel

Numerous approaches to local scour forming studies have been developed. This paper presents different scientific approaches to the scour phenomenon using Lane’s relation [1] in its modified form during laboratory studies. The original Lane’s relation is applicable in dynamic balance conditions in alluvial rivers context, and it is not an equation, but a qualitative expression which cannot be directly used to estimate the influence of a change in one parameter on the magnitude of others. Lane\u27s relation, despite its qualitative and simplified character, serves well to describe the nature of the process of forming alluvial stream channels, while modified relation allows transforming it into an equation for laboratory studies of local scour forming in prearranged clear-water equilibrium conditions and gives a new opportunity for this principle application

Using a modified Lane’s relation in local bed scouring studies in aluvial bed

Numerous approaches to the local scour studies have been developed. The research aim was to verify modified Lane’s relation in scope of local scouring phenomenon basing on laboratory studies results. Original Lane’s relation [1955] is applicable in dynamic balance conditions in alluvial rivers context. Original form is not an equation, but a qualitative expression which cannot be directly used to estimate the influence of a change in one parameter on the magnitude of others. Modified version allows transforming it into equation for dynamic equilibrium conditions in steady flow assumption and gives a new opportunity to this principle application. Two physical models of laboratory channel with rectangular cross-sections and glass panels have been constructed, with totally or partially sandy bottom. Model I assumed non-continual sediment transport, because of model construction, i.e. the solid bottom transforms into sandy bottom in the intake part. Model II assumed water structure (the weir with four slots) introducing into laboratory channel with solid bottom in its region, whereas the rest of channel was filled with sand above and below structure, i.e. continuity of sediment transport was assured. Results of research confirmed modified Lane’s relation usability in scope of local scouring phenomenon description in dynamic equilibrium conditions of alluvial sandy bed

On local scouring downstream small water structures

Background In order to regulate water flow, hydraulic structures such as weirs or checks, frequently equipped with gates, are used. Water can flow below or over the gate or, simultaneously, over and below the gate. Both diversifications of hydraulic gradient, being an effect of damming up a river by the structure and shear stresses at the bed, which exceeds the critical shear stress value, invoke the local scouring downstream the structure. This phenomenon has been studied in laboratory and field conditions for many years, however Researchers do not agree on the parameters that affect the size of the local scour and the intensity of its formation. There are no universal methods for estimating its magnitude However, solutions are sought in the form of calculation formulas typical for the method of flow through the structure, taking into account the parameters that characterize a given structure. These formulas are based on factors that affect the size of the local scours, that is, their dimensions and location. Examples of such formulas are those contained in this article: Franke (1960), Straube (1963), Tarajmovič (1966), Rossinski & Kuzmin (1969) equations. The need to study this phenomenon results from the prevalence of hydrotechnical structures equipped with gates (from small gated checks to large weirs) and from potential damage that may be associated with excessive development of local erosion downstream, including washing of foundations and, consequently, loss of stability of the structure. Methods This study verifies empirical formulas applied to estimate the geometry parameters of a scour hole on a laboratory model of a structure where water is conducted downstream the gate with bottom reinforcements of various roughness. A specially designed remote-controlled measuring device, equipped with laser scanner, was applied to determine the shape of the sandy bottom. Then the formula optimization is conducted, using Monte Carlo sampling method, followed by verification of field conditions. Results The suitability of a specially designed device, equipped with laser scanner for measuring the bottom shape in laboratory conditions was demonstrated. Simple formula describing local scour geometry in laboratory conditions was derived basing on the Straube formula. The optimized formula was verified in field conditions giving very good comparative results. Therefore, it can be applied in engineering and designing practices

Using the River Habitat Survey method in forecasting effects of river restoration

Prognozowanie efektów renaturyzacji rzeki z wykorzystaniem metody River Habitat Survey. W pracy przestawiono możliwość wykorzystania metody River Habitat Survey (RHS) do oceny przewidywanych efektów renaturyzacji rzeki Zielawy na odcinku między km 18 + 960 a km 19 + 460. Tak zwana Ramowa Dyrektywa Wodna nakłada konieczność osiągnięcia w najbliższym czasie przez rzeki europejskie dobrego stanu ekologicznego. Renaturyzacja rzek jest głównym narzędziem poprawy jakości rzek, uregulowanych według wymagań technicznych. W artykule przedstawiono propozycję renaturyzacji odcinka rzeki Zielawy według czterech wariantów robót oraz dokonano oceny, wykorzystując metodę RHS, wpływu tych prac na poprawę obecnego stanu hydromorfologicznego rzeki. Stwierdzono, że w zależności od przyjętego wariantu robót poprawa stanu odcinka rzeki jest możliwa z obecnej V klasy do IV klasy (warianty 1 i 2) lub III klasy (warianty 3 i 4)